The present invention relates generally to applicator brushes used in connection with adhesives and pertains, more specifically, to improvements in applicator brushes ordinarily furnished in adhesive containers for applying adhesives of the type formulated to set-up and harden rapidly in response to the presence of moisture.
Adhesives are available commercially which set-up and harden in response to the presence of moisture at the site where the adhesive is applied to surfaces to be bonded. In particular, adhesives comprising cyanoacrylate, known as xe2x80x9cCA adhesivesxe2x80x9d, have become quite popular for a wide variety of uses where the ability of such adhesives to harden and form an exceptionally strong bond when applied to many different surfaces encountered in the field is a significant asset. These CA adhesives, usually referred to as super-glues, currently are available commercially from several is sources, some of the more well-known brand names being KRAZY GLUE and LOCKTITE.
A characteristic of CA adhesives is the ability to harden almost immediately when in the presence of moisture. In use, CA adhesives respond to moisture in the ambient air at the site of use to set-up rapidly and quickly form the sought-after strong bond. However, while this characteristic is desirable for most uses of CA adhesives, rapid set-up and hardening in response to the presence of moisture has limited the ability to use commonly available applicator brushes in connection with CA adhesives, resulting in concomitant limitations in versatility in the use of CA adhesives, for the reason that such commonly available applicator brushes utilize bristles which ordinarily tend to carry moisture, and that moisture can cause the adhesive to set-up and harden prematurely. Thus, in the most convenient packaging of adhesives, in which an applicator brush is furnished within a container of adhesive by closing the container with a cap carrying an integral applicator brush, the bristles of the brush are immersed in adhesive carried in the container. The presence of moisture in the bristles will tend to set-up the adhesive, thereby rendering the entire package useless. In addition, once a package is opened and the applicator brush is exposed to ambient air, any moisture absorbed by the bristles of the brush and carried back to the adhesive in the container can cause unwanted hardening of the adhesive, again rendering the entire package useless. Further, any moisture carried by the bristles of an applicator brush during application of a CA adhesive at a selected site will tend to set-up and harden it the adhesive prematurely, thereby limiting the ability of the brush to distribute the adhesive evenly over the surfaces to be bonded. Thus, applicator brushes constructed with the most commonly used natural bristles, such as horse hair, goat hair, squirrel hair, and hog bristle, tend to carry moisture and are not well-suited for use in connection with CA adhesives. Likewise, nylon, which is the synthetic fiber used most commonly in applicator brushes, tends to absorb moisture and is undesirable for use with CA adhesives.
The present invention provides an improvement which enables applicator brushes having bristles constructed of synthetic polymeric fibers to resist moisture absorption and to allow use in connection with CA adhesives, as well as other moisture-responsive adhesives, without significant unwanted or premature set-up and hardening of the adhesive. As such, the present invention attains several objects and advantages, some of which are summarized as follows: Provides applicator brushes improved for use in connection with moisture-responsive adhesives without significant unwanted or premature set-up and hardening of the adhesive; resists exposure of a moisture-responsive adhesive to moisture which could cause unwanted or premature set-up and hardening of the adhesive, either during storage of the adhesive in a container or during application of the adhesive to a selected surface at the site of use; enables the use of commercially available, relatively economical synthetic polymeric fibers as bristles in applicator is brushes employed in connection with moisture-responsive adhesives, such as CA adhesives; extends the useful life of packaged moisture-responsive adhesives, such as CA adhesives, by resisting the introduction of unwanted moisture into such packages; facilitates the use of applicator brushes in applying CA adhesives and similar moisture-responsive adhesives evenly upon surfaces to be bonded; enables economical packaging of applicator brushes with CA adhesives, as well as with other moisture-responsive adhesives, for more convenient and effective distribution and use of such adhesives; promotes widespread and more versatile use of moisture-responsive adhesives, such as CA adhesives, with increased ease and reduced waste.
The above objects and advantages, as well as further objects and advantages, are attained by the present invention which may be described briefly as providing, in an applicator brush for use in connection with a moisture-responsive adhesive, the applicator brush having bristles with external surfaces for contacting the adhesive, an improvement wherein the bristles are constructed of filaments of a synthetic polymeric material treated by fluorination to establish a surface barrier along the external surfaces of the bristles for rendering the external surfaces resistant to permeation by moisture.
In addition, the present invention provides, in a method for making an applicator brush for use in connection with a moisture-responsive adhesive, the applicator brush having bristles with external surfaces for contacting the adhesive, an improvement comprising the steps of: constructing the bristles of filaments of a synthetic polymeric material; and treating the material of the bristles by fluorination to establish a surface barrier along the external surfaces of the bristles for rendering the external surfaces resistant to permeation by moisture.
Further, the present invention provides, in an adhesive package for use in connection with a moisture-responsive adhesive, the adhesive package including a container for the adhesive and an applicator brush for extending into the container to be in contact with the adhesive in the container, the applicator brush having bristles with external surfaces for contacting the adhesive, an improvement wherein the bristles are constructed of filaments of a synthetic polymeric material treated by fluorination to establish a surface barrier along the external surfaces of the bristles for rendering the external surfaces resistant to permeation by moisture.